中低温填充床储热系统分层填充方式对其储热特性的影响研究  

Study on the Impact of Packing Methods on Thermal Performance of Packed-bed Thermal Storage Systems at Medium-low Temperature

作　　者：吕鹏飞 赵文杰[1] 刘兰兰 刘锋 雷广平[1] 刘汉涛[1] LüPengfei;ZHAO Wenjie;LIU Lanlan;LIU Feng;LEI Guangping;LIU Hantao(School of Energy and Power Engineering,North University of China,Taiyuan 030051,China)

机构地区：[1]中北大学能源与动力工程学院,太原030051

出　　处：《工程热物理学报》2024年第10期2930-2938,共9页Journal of Engineering Thermophysics

基　　金：国家自然科学基金青年项目(No.52106213);山西省基础研究计划资助项目(No.20210302124207);山西省省筹资金资助回国留学人员科研项目(No.2020-116)。

摘　　要：通过构建填充床相变储热的物理与数学模型,基于有限元法在宏观尺度下研究了中低温条件下多层变径填充和多层级联填充对填充床储热系统储热特性的影响机理。在多层变径以及级联填充床储热系统中,利用相变胶囊液相率、温度分布、储热速率、[火用]效率等指标对其储热性能进行综合分析。结果表明在中低温应用条件下,双层变径填充方式可有效保证常规相变胶囊填充床的经济高效性,胶囊对d=30:10 mm的双层变径储热系统的储热速率相较d=30 mm单层填充床储热系统提高了27%;将常规相变胶囊转换为相变微胶囊填充可进一步提升系统综合储热性能,储热速率相对单层d=30 mm储热系统至少提升1.73倍,[火用]效率提高到78%以上,但单层填充方式是相变微胶囊储热系统的最优结构。岩石–相变微胶囊级联填充床储热系统结合了显热与相变储能优势,是一种在保证经济性条件下的填充床储热系统优化结构。By constructing physical and mathematical models of composite thermal storage in packed-bed systems,the impact mechanisms of multi-layer variable diameter filling and multi-layer cascade filling on the thermal storage characteristics of the packed-bed thermal storage system were studied at macroscopic scale based on the finite element method under medium and low temperature conditions.In the packed-bed thermal storage systems with multi-layer variable diameter and cascade filling,comprehensive analysis of indicators such as the liquid phase fraction of phase change capsules,temperature distribution,thermal storage rate,and thermal storage efficiency were conducted to evaluate their thermal storage performance.The results showed that for conventional phase change capsule packed-bed systems with double-layer variable diameter is the economical and efficient structure under medium and low temperature,and the thermal storage rate of the d=30:10 mm system increased by 27%compared to the single-layer system with d=30 mm.Converting conventional phase change capsules into phase change microcapsule can further improve the overall thermal storage performance of the system.The thermal storage rate is at least 1.73 times higher than that of the single-layer system with d=30 mm,and the exergy efficiency is over 78%.However,the single-layer filling method is the optimal structure of the phase change microcapsule thermal storage system.The rock-phase change microcapsule cascaded packed-bed thermal storage system combines the advantages of sensible and latent thermal storage,making it an optimized structure for packed-bed thermal storage systems under economic conditions.

关 键 词：相变胶囊 储热 填充床 级联方式 数值模拟 

分 类 号：TK02[动力工程及工程热物理]